Metabolism of 3,4-Benzpyrene in Mice

Abstract

IF 3,4-benzpyrene is introduced into a mouse, it is eventually excreted as the phenol 8-hydroxy-benzpyrene^1,2. It has been established that this transformation proceeds by various steps^3,4. Four different benzpyrene derivatives have now been separated from extracts of various fresh tissues; they are provisionally termed X₁, X₂, F₁ and F₂, because they are responsible for the 'BPX' and 'BPF' fluorescences that Peacock⁵ and Chalmers⁶ discovered in the liver, bile, intestine and fæces of various animals after application of benzpyrene. The separation of X₁, X₂, F₁ and F₂ has been effected by fluorescence chromatography and selective extraction, using alumina and silica as adsorbents and acetone, benzene, xylene, petroleum ether, methyl, ethyl and amyl alcohols and water as solvents. X₁ and X₂ occur in vivo not only in the liver and digestive system but also in the lung, kidney cortex, subcutaneous tissue, skin (after painting with benzpyrene), and in the mammary glands as evidenced by the milk of mice; F₁ and F₂ occur in the large intestine and fæces, and occasionally in the lungs. The amount of fresh uncontaminated mouse urine did not suffice for a definite analysis, but there were indications of the presence of the X derivatives. Post mortem, all X-bearing tissues show slowly increasing amounts of the F derivatives unless they are kept in formol. The 3,4-benzpyrene-5,8-quinone that Berenblum and Schoental² discovered in the fæces never appeared in fresh tissues.